International Journal of Engineering Research ISSN: 2319-6890)(online),2347-5013(print) Volume No.5 Issue: Special 6, pp: 1129 - 1254 20 May 2016 ICCIT16 @ CiTech, Bengaluru doi: 10.17950/ijer/v5i6/019 Page 1222 Effect of AL 2 O 3 and fly ash reinforced particulates for fatigue behavior of the AL6061T6 alloy matrix composites. Arun.L.R 1* , Dr.Suneel Kumar N.Kulkarni 2 1 Department of Mechanical engineering, Cambridge institute of technology, Bangalore, India 2 Professor BTL Institute of Technology, Bangalore, India E-mail: arunlrg@gmail.com Abstract --- The Aluminium metal matrix composites are being considered for their strength to weight ratio and better mechanical characteristics, they find application in the field of automotive, aerospace, and construction. In present work the composite material is fabricated with fly ash composition of 9%,12%,&15% weight fraction and Alumina (Al2O3) with 6% weight fraction using vortex casting. SEM and EDS analysis revealed the particulate distribution as even and there by Mechanical test are carried out. It was observed that tensile and hardness properties were excellent when compared with monolithic alloy and the fatigue behaviour revealed that composite with 6% Al 2 O 3 and 15 % fly ash has good fatigue life compared with monolithic alloy. The fatigue test was conducted using fully reversed cycle R=-1 using rotating bending machine at room temperature. Loads are defined by considering 0.5UTS, 0.7UTS and 0.9UTS to plot S-N curve. I. Introduction The particulate composite can be prepared by injecting the reinforcing particles into liquid matrix through liquid metallurgy by casting. Among the entire liquid state production routes, stir casting¹ is the simplest and cheapest one. The only problem associated with this process is the non uniform distribution of the particulate due to poor wet ability and gravity regulated segregation. Mechanical properties of composites are affected by the size, shape and volume fraction of the reinforcement, matrix material and reaction at the interface. To over come this problem magnesium is added to molten aluminium about 2% to achieve wettability. To ensure the proper mixing of particulate material a required amount of controlled vortex formation is produce during stiring operation. Fly ash was extracted from Raichur thermal plant and Al 2 O 3 from locally. The magnesium removes oxygen from surface thus by eliminating gas layers and improving wettability. Hybrid Aluminium MMCs containing reinforcements such as Al 2 O 3 with fly ash is available in the literatures [1-18]. Madeva Nagaral [1] et.al studied the effect of aluminum oxide particle reinforcements on mechanical properties of 6061 Al alloy composites. Author fabricated 6061Al composites with different weight percentage of Al 2 O 3 particles up to 9% by using stir casting technique. Author concluded that tensile strength yield strength of the composites is increases with increase in weight percentage of Al 2 O 3 reinforcement particles. Sajjadi.S.A[2]el.al Fabricated A356 alloy composites with stir casting with different weight percentage of Al 2 O 3 reinforcements and with different reinforcement particle size. Author stated that compressive strength, tensile strength of the composites increased. Author also investigated the best stir speed for uniform mixing of reinforcements is 300rpm. Author observed that wettability of the reinforcement’s particles within molten matrix decreases with increase reinforcement percentage and decreases with reinforcement particle size. It also revealed that hardness and porosity of the composites increases with increase in weight percentage of reinforcement and decreases in particle size. K. Radhakrishna [3] et.al studied effects of copper and fly ash particulate reinforcements with aluminium alloy as matrix metal. Author concluded that reinforcement up to 15 percent are successfully dispersed in the matrix. Hardness and Wear resistance of the composites increased as the weight percentage of the reinforcements was increased. M. Kok [4] has studied the effect of Al2O3 particles content and size of the particles on the mechanical properties of the composites produced by vortex method. In his work author added Al2O3 particles up to 30 weight % with 2024 Al alloy as a matrix composites. Author concluded that the mechanical properties like hardness and tensile strength of the composites increases with decrease in particles size and increases with increase in weight percentage of the reinforcement particles. B G Park [5] et.al has investigated the high cycle fatigue behaviour of COMRAL-85 and 6061 aluminium- magnesium-silicon alloy reinforced with Al 2 O 3 ceramic particles manufactured by liquid metallurgy route and by powder metallurgy. Author carried out fatigue tests for a stress ratio of R=-1 (fully reversed loading condition). Author concluded that all the composites were very similar on their fatigue threshold results. Also author stated that the fatigue properties of the composites produced by the powder metallurgy technique exhibits better results than the composites produced by liquid metallurgy technique. This is because of defects in the manufacturing technique of liquid metallic.